This disclosure generally relates to emergency power systems that provide power to systems of an air vehicle in the absence of power produced by primary power sources. More particularly, this disclosure relates to a system and method for utilizing power from multiple secondary power sources in the absence of power from the primary power source.
An air vehicle includes a primary power source such as a gas turbine engine that can produce not only thrust to propel the vehicle but also electrical and hydraulic power to actuate and run various on-board systems. Such systems can include navigation devices, environmental controls, along with any other system that is utilized on-board an air vehicle for controlling and directing the air vehicle. Emergency power can be provided by many different devices including those generating power from the environment, such as a ram air turbine assembly. Moreover, emergency power may also be provided by storing energy such as is accomplished by using electricity drawn from batteries or converting fuel into energy through the use of a power conversion device. Each form of emergency power has advantages that are tempered by costs that affect normal air vehicle performance. Such costs, for example, include weight, space and complexity.